#!/usr/bin/env bash
#
# qvm-status - Display VM state, configuration, and connection information
#
# Shows current VM status including:
# - Running state (PID, uptime, SSH port)
# - Mounted workspaces from workspaces.json
# - Cache directory status
# - Base image and overlay details
# - Connection hints for SSH and run commands
#
# Exit codes:
#   0 - VM is running
#   1 - VM is stopped

set -euo pipefail

# Source common library for shared functions and constants
readonly QVM_LIB_DIR="${QVM_LIB_DIR:-$(dirname "$0")/../lib}"
source "${QVM_LIB_DIR}/common.sh"

# Additional color codes for status display
if [[ -t 1 ]]; then
    readonly COLOR_SUCCESS='\033[0;32m'   # Green
    readonly COLOR_HEADER='\033[1;37m'    # Bold White
    readonly COLOR_DIM='\033[0;90m'       # Dim Gray
else
    readonly COLOR_SUCCESS=''
    readonly COLOR_HEADER=''
    readonly COLOR_DIM=''
fi

#
# format_bytes - Convert bytes to human-readable format
# Args: $1 - size in bytes
# Returns: formatted string (e.g., "1.5G", "256M", "4.0K")
#
format_bytes() {
    local bytes="$1"
    if (( bytes >= 1073741824 )); then
        printf "%.1fG" "$(echo "scale=1; $bytes / 1073741824" | bc)"
    elif (( bytes >= 1048576 )); then
        printf "%.1fM" "$(echo "scale=1; $bytes / 1048576" | bc)"
    elif (( bytes >= 1024 )); then
        printf "%.1fK" "$(echo "scale=1; $bytes / 1024" | bc)"
    else
        printf "%dB" "$bytes"
    fi
}

#
# get_uptime - Calculate VM uptime from PID
# Args: $1 - process PID
# Returns: uptime string (e.g., "2h 15m", "45m", "30s")
#
get_uptime() {
    local pid="$1"
    
    # Get process start time in seconds since epoch
    local start_time
    start_time=$(ps -p "$pid" -o lstart= 2>/dev/null | xargs -I{} date -d "{}" +%s)
    
    if [[ -z "$start_time" ]]; then
        echo "unknown"
        return
    fi
    
    local current_time
    current_time=$(date +%s)
    local uptime_seconds=$((current_time - start_time))
    
    # Format uptime
    local hours=$((uptime_seconds / 3600))
    local minutes=$(( (uptime_seconds % 3600) / 60 ))
    local seconds=$((uptime_seconds % 60))
    
    if (( hours > 0 )); then
        printf "%dh %dm" "$hours" "$minutes"
    elif (( minutes > 0 )); then
        printf "%dm %ds" "$minutes" "$seconds"
    else
        printf "%ds" "$seconds"
    fi
}

#
# show_file_info - Display file status with size and modification time
# Args: $1 - file path
#       $2 - label (e.g., "Base Image")
#
show_file_info() {
    local file="$1"
    local label="$2"
    
    if [[ -f "$file" ]]; then
        local size_bytes
        size_bytes=$(stat -c %s "$file" 2>/dev/null || echo "0")
        local size_human
        size_human=$(format_bytes "$size_bytes")
        
        local mod_time
        mod_time=$(stat -c %y "$file" 2>/dev/null | cut -d. -f1)
        
        echo -e "  ${COLOR_SUCCESS}✓${COLOR_RESET} $label: ${COLOR_INFO}$size_human${COLOR_RESET} ${COLOR_DIM}(modified: $mod_time)${COLOR_RESET}"
    else
        echo -e "  ${COLOR_WARN}✗${COLOR_RESET} $label: ${COLOR_WARN}missing${COLOR_RESET}"
    fi
}

#
# show_dir_info - Display directory status
# Args: $1 - directory path
#       $2 - label (e.g., "Cargo Home")
#
show_dir_info() {
    local dir="$1"
    local label="$2"
    
    if [[ -d "$dir" ]]; then
        echo -e "  ${COLOR_SUCCESS}✓${COLOR_RESET} $label: ${COLOR_DIM}$dir${COLOR_RESET}"
    else
        echo -e "  ${COLOR_WARN}✗${COLOR_RESET} $label: ${COLOR_WARN}not created${COLOR_RESET}"
    fi
}

#
# show_workspaces - Display mounted workspaces from workspaces.json
#
show_workspaces() {
    if [[ ! -f "$QVM_WORKSPACES_FILE" ]]; then
        echo -e "  ${COLOR_DIM}No workspaces mounted${COLOR_RESET}"
        return
    fi
    
    # Check if file is valid JSON and has workspaces
    local workspace_count
    workspace_count=$(jq 'length' "$QVM_WORKSPACES_FILE" 2>/dev/null || echo "0")
    
    if (( workspace_count == 0 )); then
        echo -e "  ${COLOR_DIM}No workspaces mounted${COLOR_RESET}"
        return
    fi
    
    # Parse and display each workspace
    jq -r 'to_entries[] | "\(.key)|\(.value.host_path)|\(.value.guest_path)"' "$QVM_WORKSPACES_FILE" 2>/dev/null | while IFS='|' read -r hash host_path guest_path; do
        echo -e "  ${COLOR_SUCCESS}✓${COLOR_RESET} $hash: ${COLOR_INFO}$host_path${COLOR_RESET} → ${COLOR_DIM}$guest_path${COLOR_RESET}"
    done
}

#
# main - Main status display logic
#
main() {
    # Header
    echo -e "${COLOR_HEADER}QVM Status${COLOR_RESET}"
    echo ""
    
    # VM State
    echo -e "${COLOR_HEADER}VM State:${COLOR_RESET}"
    
    if is_vm_running; then
        local pid
        pid=$(cat "$QVM_PID_FILE")
        
        local ssh_port
        if [[ -f "$QVM_SSH_PORT_FILE" ]]; then
            ssh_port=$(cat "$QVM_SSH_PORT_FILE")
        else
            ssh_port="unknown"
        fi
        
        local uptime
        uptime=$(get_uptime "$pid")
        
        echo -e "  ${COLOR_SUCCESS}✓${COLOR_RESET} Running"
        echo -e "  ${COLOR_DIM}PID:${COLOR_RESET}     $pid"
        echo -e "  ${COLOR_DIM}SSH:${COLOR_RESET}    localhost:$ssh_port"
        echo -e "  ${COLOR_DIM}Uptime:${COLOR_RESET} $uptime"
    else
        echo -e "  ${COLOR_WARN}✗${COLOR_RESET} Stopped"
    fi
    
    echo ""
    
    # Workspaces
    echo -e "${COLOR_HEADER}Mounted Workspaces:${COLOR_RESET}"
    show_workspaces
    echo ""
    
    # Cache Directories
    echo -e "${COLOR_HEADER}Cache Directories:${COLOR_RESET}"
    show_dir_info "$QVM_CARGO_HOME" "Cargo Home"
    show_dir_info "$QVM_CARGO_TARGET" "Cargo Target"
    show_dir_info "$QVM_PNPM_STORE" "PNPM Store"
    show_dir_info "$QVM_SCCACHE" "SCCache"
    echo ""
    
    # VM Images
    echo -e "${COLOR_HEADER}VM Images:${COLOR_RESET}"
    show_file_info "$QVM_BASE_IMAGE" "Base Image"
    show_file_info "$QVM_OVERLAY" "Overlay"
    echo ""
    
    # Connection Hints (only if VM is running)
    if is_vm_running; then
        local ssh_port
        ssh_port=$(cat "$QVM_SSH_PORT_FILE" 2>/dev/null || echo "unknown")
        
        echo -e "${COLOR_HEADER}Connection:${COLOR_RESET}"
        echo -e "  ${COLOR_INFO}SSH:${COLOR_RESET}     qvm ssh"
        echo -e "  ${COLOR_INFO}Run cmd:${COLOR_RESET} qvm run <command>"
        echo -e "  ${COLOR_INFO}Direct:${COLOR_RESET}  ssh -p $ssh_port root@localhost"
        echo ""
        
        # Exit success if running
        exit 0
    else
        echo -e "${COLOR_HEADER}Quick Start:${COLOR_RESET}"
        echo -e "  ${COLOR_INFO}Start VM:${COLOR_RESET} qvm start"
        echo ""
        
        # Exit failure if stopped
        exit 1
    fi
}

# Execute main
main "$@"